Ashley writes about her newly planted knockout rose problem: “I planted my double knockout rose bush 2 days ago and the leaves are drooping and so are the rose buds. I have clay soil so I dug the hole and planted my rose bush and filled the hole back up with garden soil and “black cow” (brand name) manure. Did I do something wrong. I have watered everyday also”.

My response:
Hi Ashley, you basically did everything right; you added some composted organic matter to the soil, you’re watering your double knockout every day to get it off to a good start, you waited to fertilize it, but did you check the drainage of the planting area before you planted your double knockout rose?

The trouble with clay soil is that it is usually poorly draining, and if you dig a hole in clay soil, plant a rose in it and backfill it with garden soil or compost, or even a good quality loam, after watering it the water will just sit there in the planting hole with nowhere to go.

It’s like the rose is sitting in a bath with no plug. The water easily percolates down through the new soil the hole has been refilled with but when it hits the clay sides and the clay bottom of the hole you dug, the water just sits there; it has nowhere to go and will drain away ever so slowly.

This is most likely the reason your knockout rose is drooping or wilting, especially with the daily watering (which under ordinary circumstances would be fine in well drained soil). It’s sitting in water for too long because it’s not draining away quickly enough.

It’s really important to check the drainage of the area you are going to plant a knock out rose (or any rose for that matter) in before planting. You can do this by digging a hole about 30 cm (1 foot) deep, filling it with water and seeing how long it takes to drain.

If it takes any longer than a day or so, you need to either put in some kind of underground drainage or build a raised garden bed in that area about a foot (30 cm) high, otherwise your roses are going to be sitting in water for long periods which in turn will rot the roots and no roots means no uptake of water or nutrients to the plant.

Also in regards to the cow manure, the brand you used is composted cow manure, and seeing it is composted that’s perfect; it shouldn’t be contributing to the drooping problem.

In this situation, I feel the drooping problem stems from the poor drainage of the clay soil. If you can, dig a hole near the planting area to check the drainage. My guess is that the drainage is going to be pretty poor.

If it were my knock out rose and it was in poorly draining clay soil, I would dig it back out (the root ball should still be pretty much intact as it was in the pot after only a couple of days if it was a potted rose) and put it back into the pot it came from or one of similar size, and do this either early morning or late afternoon, not while sun is on the plant.

If it was a bare-root knockout rose, pot it up into a pot that’s big enough for the roots to spread out over a mound you make at the base of the pot with good quality potting soil and deep enough that the rose’s main stem sits in the potting mix at the original soil level it was planted at before it was lifted from the ground to be sold. You can usually tell by looking along the main stem (under the bud graft if it was grafted) and seeing a slight change in color there (usually darker).

Do not let the roots dry out while doing this; have the pot and potting mix ready to put the dug up rose straight into.

Once re-potted, water the knockout rose straight away and follow that with some liquid seaweed mixed in a watering can at half strength to help the rose get over the transplant shock. It will be fine in the pot; just regularly water it and give it some liquid seaweed (made up at half strength) once a week (after it’s been watered first). Do not give it any fertilizer at this stage. (Liquid seaweed on its own is not a fertilizer)

Now getting back to the garden bed, you’ll have to decide on a way to improve the drainage of that particular area, either by using underground piping, building a raised garden bed or maybe finding another area of the garden that has better drainage, as roses hate wet feet. Here’s an article I wrote a while ago about How To Plant Knockout Roses that may help you in the future.